This invention relates to an improved process for comminuting and drying various types of garbage and refuse. More particularly, the invention relates to an improved process for comminuting, heating, compressing and drying nutrient containing wastes such as food wastes produced by dining establishments, sewage matter, animal wastes such as occurs where animals such as cattle and hogs are kept for commercial meat production, etc., to produce a bacteria free, dried product that may be used as animal feed fertilizer or the like. It is to be understood that the words refuse, garbage and wastes, as used herein, include all types of nutrient containing material as well as other material that is intended to be disposed of in a clean and dried form.
U.S. Pat. No. 1,101,129, issued June 23, 1914, U.S. Pat. No. 1,493,335, issued May 6, 1924, and U.S. Pat. No. 2,089,978, issued Aug. 17, 1937, disclose various processes and apparatus for treating and handling material such as refuse. U.S. Pat. No. 1,493,335 discloses a process whereby refuse is dried by pressing the refuse between a roller and the surface of a heated plate, thereby accomplishing heating and disintegration simultaneously. U.S. Pat. No. 1,101,129 teaches drying refuse by heating the refuse in an oven. U.S. Pat. No. 2,089,978 teaches drying the refuse by passing it on a conveyor through an oven.
Refuse discarded from dining establishments contains a high degree of nutrients since such refuse is primarily composed of food waste. Such refuse is typically discarded by burning it or dumping the refuse in a refuse dump where it may be covered with earth or left uncovered as desired. No benefit is usually realized from the various nutrients contained in the refuse and the costs of handling the refuse is considered a serious burden on society.
Where animals, such as cattle, hogs and the like are kept in a closely confined area, typically referred to as a feed lot for the purpose of commercial meat production, the animal wastes become a serious problem because the wastes cannot be effectively disposed of in ordinary sewage treatment plants. It is the typical practice in the industry to allow the feed lots to accumulate the animal wastes for long periods of time and to periodically remove such wastes with scraping machines. The result of such handling requires the animals to live in an unsanitary environment where diseases can develop that render the animals unfit for commercial production. Moreover, the animal wastes typically cause an odor problem that has the effect of contaminating large areas of the environment.
Where pesticides are employed to kill bacteria carrying insects such as flies to prevent the development of diseases, the pesticide materials themselves create a problem of contaminating the ground water about feed lots which ground water, in due course, finds its way into the streams and rivers and causes water pollution. It is desirable to eliminate the need for using large amounts of pesticide materials in commercial meat production.
In hospitals it is frequently desirable to dispose of diseased wastes and materials. The problem of handling and adequately disposing of hospital wastes is typically exceedingly expensive because of the necessity to prevent spreading of human diseases. It is necessary that the wastes be subjected to heat for a sufficient amount of time to dispose of any bacteria contained therein and to render the wastes free from rapid water absorption in order to prevent bacteria from forming in the processed waste material within a reasonable amount of time following processing of the same.
It is therefore a primary object of the present invention to provide a novel method for processing refuse and waste materials having a nutrient content in such manner that the waste materials may be employed as animal feed and may be disposed of in an inexpensive and sanitary manner.
It is a further object of the present invention or provide novel method for processing refuse in such manner that the processed refuse may be stored for long periods of time without becoming contaminated by bacteria.
It is also an important object of the present invention to provide novel method for processing sewage wastes to remove the water content thereof and to yield a solid, compressed and dried product that may be efficiently utilized as commercial fertilizer or may be efficiently and inexpensively disposed of without causing pollution of the environment.
It is an even further object of the present invention to provide a novel method for processing refuse materials where there is yielded a flake or platelet-like product that does not have an affinity for absorption of water from the atmosphere.
It is an object of the present invention to provide a method for grinding and drying refuse.
It is another object of the present invention to provide a method for grinding and drying food waste.
It is still another object of the present invention to provide a process for producing fertilizer and animal food from disposed food.